The Magnetotransport Properties and a Neutron Diffraction Study of Sr 2– x Nd x FeMoO 6 Double Perovskites

New electron‐doped derivatives of the Sr 2 FeMoO 6 double perovskite have been studied. We report on the synthesis of the Sr 2– x Nd x FeMoO 6 ( x = 0, 0.2, 0.4 and 0.6) perovskite series by a wet chemistry procedure and its characterization. The evolution of the crystal and magnetic structure has been analyzed from neutron powder diffraction data. The partial replacement of Sr 2+ cations by higher valence Nd 3+ cations induces an injection of electrons into the Fe/Mo sublattice. A bond‐valence study demonstrates that this electron‐injection preferentially affects the Mo orbitals. This substitution leads to a distortion of the structure from tetragonal ( I 4/ m ) to monoclinic ( P 2 1 / n ) at room temperature for x  ≥ 0.4 and an increase of the disorder between Fe and Mo cations. This effect has severe consequences for the magnetic properties, notably a reduction of the saturation magnetization and a non‐monotonic behavior of the Curie temperature. Magnetotransport measurements show a significant increment of the magnetoresistance at low temperature for high values of x . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)